'It is not illegal to sell horsemeat in burgers, only to fail to declare it.' Photograph: Monkey Business Images/Rex Features

"You get what you pay for" applies to food as much as anything else, and the only surprise about the latest adulteration scandal, in which beefburgers at rock bottom prices turn out to contain horsemeat and traces of pig, is perhaps that they contain meat at all.

The trajectory of the scandal has a familiarity to it too. It began with the announcement on Tuesday evening by the Food Safety Authority of Ireland that it had detected other animals in 85% of all beefburger samples it had tested two months previously. Tesco Everyday Value beefburgers topped the adulteration league, being 29% horsemeat, but Lidl, Aldi and others were caught up in it too, with more than a third of all the beefburgers tested containing some horse.

The European beef-processing industry is, like most other sectors of today's globalised food chain, dominated by a handful of players. One is the Irish-based ABP Group (formerly Anglo Beef Processors), which owns Silvercrest and Dalepak, two of the three companies named by the FSA Ireland as sources of the burgers, the third being Liffey Foods, which also supplies several large retailers.

The other big players in the red meat sector are the Irish-based Dawn Meats, which supplies M&S, whose burgers got a clean bill of health as 100% beef, and the Dutch-based poultry and meat giant Vion, which has not been implicated either. Vion is, however, currently divesting itself of its red meat operations in the UK and further concentration of the industry is likely. If you are a beef farmer wanting to sell your cattle, or a supermarket buyer wanting to source meat, you have little choice of processor.

The mergers and takeovers that created this high concentration of ownership were a response to the concentration of buying power in the hands of a few dominant retailers. The big meat processors have been under constant pressure from supermarkets to keep prices down and to produce special offers for shoppers as food inflation has taken off just as household budgets have shrunk with the recession. This despite the fact that beef prices on the commodity markets have been near historic highs, because the cost of grain needed to feed cattle has also been at record highs, and because the Chinese have been buying up stocks. In a market that functioned properly, prices would adjust to bring supply and demand into balance, but near-monopoly powers have long distorted the UK food market. Inevitably, it looks as though corners have been cut and supermarkets will reap the whirlwind in reputational damage.

Little else is likely to happen. Prosecutions in previous food adulteration scandals have been few and far between; fines, usually for minor labelling breaches rather than for any more serious offence, have been derisory for companies whose turnovers are counted in billions. It is not illegal to sell horsemeat in burgers, only to fail to declare it.

Intense lobbying has ensured that the meat industry is now regulated with a light touch. Meat inspection by the government's Meat Hygiene Service has been steadily deregulated over the past two decades. The MHS vet in a large abattoir cuts a lonely figure and is often in any case absent at night. Current proposals before Europe would make the industry largely self-policing. The Food Standards Agency, meanwhile, was itself eviscerated by the coalition government as part of the Conservatives' "bonfire of the quangos". Its previous chief executive Tim Smith is now Tesco's technical director and dealing with the scandal on the other side of the fence. Trading standards officers, who would be responsible for detecting mislabelled meat have also been cut drastically by the coalition. There were 26% fewer inspections in 2011-12 than in 2009-10 and a 29% drop in prosecutions.

Because supply chains are so long and processors use subcontractors to supply meat when the volume of orders changes dramatically at short notice, it is all too easy for mislabelled, poorer quality, or downright fraudulent meat to be substituted for what is specified in big abattoirs and processing plants. Some of the traces of pig found may have come from cross-contamination in factories where both pigs and cattle are slaughtered, although it is hard to explain away the beefburger with 29% horse, and in that case ABP is pointing the finger at two of its continental European suppliers.

It is not the first time the Irish meat processing sector has come under scrutiny. The UK FSA set up a food fraud taskforce following a major investigation in to repacking and relabelling of meat in a large wholesale cold store in Northern Ireland in 2005. Inspectors from mainland UK were brought in to scrutinise the work of Irish Department of Agriculture veterinary inspectors in that case.